Nothing contained in sections 393.550 to 393.565 shall affect the other rights of access which may be available to the utility company against the utility customer in default under applicable law, or under applicable rules, regulations and tariffs of the utility company, or of the Missouri public service commission; except that no gas or electric utility company, as defined in subdivision (5) of section 393.550, shall terminate utility service to an entire residence, as defined in subdivision (4) of section 393.550, solely by reason of the delinquency in payment of one or more customers, when there are one or more other customers at the residence who are not for any lawful reason, including but not limited to delinquency in payment, subject to termination of utility service. Nothing contained in sections 393.550 to 393.565 shall be construed to prevent a utility company from discontinuing utility service to any residence for any other lawful purpose.